La0.6Sr0.2Ca0.2Fe0.8Ni0.2O3 thin films obtained by pulsed laser ablation: Effect of the substrate on the electrochemical behavior

Polycrystalline La0.6Sr0.2Ca0.2Fe0.8Ni0.2O3 (LSCFN) samples were prepared by the liquid mix process at 600 °C. The analysis of X-ray powder diffraction (XRD) patterns indicated that the sample was single phase and crystallized in an orthorhombic structure (Pbnm). High quality LSCFN films have been deposited on different yttria-stabilized zirconia (YSZ) substrates by conventional painting method and by pulsed laser deposition (PLD). The structure of the films was analyzed by X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). All films are polycrystalline with a marked texture exhibiting pyramidal grains in the surface with different size distribution. Nanostructured cathode thin films with vertically aligned nanopores (VANP) have been obtained. Electrochemical Impedance Spectroscopy (EIS) measurements of LSCFN/YSZ/LSCFN test cells were performed. Half cells deposited by painting showed higher resistance than those deposited by PLD. Experimental results indicate that the PLD deposition on (110) single crystal substrate is the best. The area specific resistance value at 850 °C is 0.21 Ωcm2 pointing out that strontium can be substituted for calcium in the material without compromising the electrochemical properties.